Sensor assembly apparatus and methods for continuous glucose monitors

ABSTRACT

In some embodiments, a sensor assembly for a continuous glucose monitoring system is provided that includes (1) a sensor carrier having a sensor unit receiving area and an electronics receiving area, the electronics receiving area including a substrate; (2) a sensor unit having a sterilized region, the sterilized region including at least a portion of a sensor and an introducer; and (3) electronics for the continuous glucose monitoring system. The sensor unit is positioned within the sensor unit receiving area of the sensor carrier and the electronics are positioned on the substrate within the electronics receiving area of the sensor carrier so as to form a sensor assembly having the sensor electrically connected to the substrate of the electronics receiving area while maintaining sterilization of the sterilized region of the sensor unit. Numerous other aspects are provided.

RELATED APPLICATIONS

The present application is a continuation application claiming priorityto and the benefit of U.S. patent application Ser. No. 15/974,680, filedMay 8, 2018, and titled “SENSOR ASSEMBLY APPARATUS AND METHODS FORCONTINUOUS GLUCOSE MONITORS,” which claims priority to and the benefitof U.S. Provisional Patent Application No. 62/503,859, filed May 9,2017, and titled “SYSTEMS, APPARATUS AND METHODS FOR CONTINUOUS GLUCOSEMONITOR SENSOR INSERTION,” and U.S. Provisional Patent Application No.62/657,612, filed Apr. 13, 2018, and titled “SENSOR ASSEMBLY APPARATUSAND METHODS FOR CONTINUOUS GLUCOSE MONITORS,” each of which is herebyincorporated by reference herein in its entirety for all purposes.

FIELD

The present disclosure relates generally to continuous glucosemonitoring (CGM) and more particularly to apparatus and methods forsensor assemblies for CGMs.

BACKGROUND

Existing CGM products provide frequent measurements of a patient'sglucose levels without the need for each such measurement to beaccompanied by the drawing of blood, such as by “finger sticks.” CGMproducts may include a sensor portion that is inserted so as to belocated under the skin, and a processing portion that is adhered to theouter surface of the skin, for example the abdomen or back of the upperarm. These CGM products are worn for a number of days before beingremoved and replaced.

The sensor that has been inserted under the skin provides a signal tothe processing portion of the CGM product, and that signal is indicativeof the patient's blood glucose level. These measurements may be madeautomatically many times throughout the day (e.g., every 5 minutes or atsome other interval).

The processing portion of a CGM product may include electrical circuitryfor interpreting the signal provided by the sensor, and for storingand/or communicating information regarding the patient's blood glucoselevels.

SUMMARY

Embodiments In some embodiments, a sensor assembly for a continuousglucose monitoring system is provided that includes (1) a sensor carrierhaving a sensor unit receiving area and an electronics receiving area,the electronics receiving area including a substrate; (2) a sensor unithaving a sterilized region, the sterilized region including at least aportion of a sensor and an introducer; and (3) electronics for thecontinuous glucose monitoring system. The sensor unit is positionedwithin the sensor unit receiving area of the sensor carrier and theelectronics are positioned on the substrate within the electronicsreceiving area of the sensor carrier so as to form a sensor assemblyhaving the sensor electrically connected to the substrate of theelectronics receiving area while maintaining sterilization of thesterilized region of the sensor unit.

In some embodiments, an insertion device for a continuous glucosemonitoring system is provided that includes (1) an insertion unit; (2) asensor carrier positioned within the insertion unit and having a sensorunit receiving area and an electronics receiving area, the electronicsreceiving area including a substrate; (3) a sensor unit having asterilized region, the sterilized region including at least a portion ofa sensor and an introducer; and (4) electronics for the continuousglucose monitoring system. The sensor unit is positioned within thesensor unit receiving area of the sensor carrier and the electronics arepositioned on the substrate within the electronics receiving area of thesensor carrier so as to form a sensor assembly having the sensorelectrically connected to the substrate of the electronics receivingarea while maintaining sterilization of the sterilized region of thesensor unit. The insertion device also includes a removable coverattached to the insertion unit that interfaces with the sensor unit suchthat removal of the removable cover exposes the introducer and thesensor.

In some embodiments, a sterilized sensor unit for a continuous glucosemonitor is provided that includes (1) a sensor, an introducer having aninsertion shaft, and an insertion shaft cover; and (2) a sensor housinghaving (a) a first end configured to receive the insertion shaft of theintroducer; (b) a second end having a sealing surface configured to sealagainst the insertion shaft cover; and (c) an insertion shaft openingthat extends between the first end and the second end and having a widththat allows the insertion shaft of the introducer to travel through theopening. A portion of the sensor and insertion shaft of the introducerare positioned within the insertion shaft opening of the sensor housing.The insertion shaft cover is sealingly coupled to the second end of thesensor housing, the insertion shaft cover having an inner region. Thesensor housing, the introducer and the insertion shaft cover form asealed region that includes the inner region of the insertion shaftcover. The sealed region and all components within the sealed region aresterilized.

In some embodiments, a method of forming a sensor assembly for acontinuous glucose monitoring system includes (1) providing a sensorcarrier having a sensor unit receiving area and an electronics receivingarea, the electronics receiving area including a substrate; (2)providing a sensor unit having a sterilized region, the sterilizedregion including at least a portion of a sensor and an introducer; (3)providing electronics for the continuous glucose monitoring system; and(4) positioning the sensor unit within the sensor unit receiving area ofthe sensor carrier and positioning the electronics on the substratewithin the electronics receiving area of the sensor carrier so as toform a sensor assembly having the sensor electrically connected to thesubstrate of the electronics receiving area while maintainingsterilization of the sterilized region of the sensor unit.

In some embodiments, a method of forming an insertion device for acontinuous glucose monitoring system includes (1) providing a sensorcarrier having a sensor unit receiving area and an electronics receivingarea, the electronics receiving area including a substrate; (2)providing a sensor unit having a sterilized region, the sterilizedregion including at least a portion of a sensor and an introducer; (3)providing electronics for the continuous glucose monitoring system; (4)positioning the sensor unit within the sensor unit receiving area of thesensor carrier and positioning the electronics on the substrate withinthe electronics receiving area of the sensor carrier so as to form asensor assembly having the sensor electrically connected to thesubstrate of the electronics receiving area while maintainingsterilization of the sterilized region of the sensor unit; (5) providingan insertion unit; (6) positioning the sensor carrier within theinsertion unit; and (7) attaching a removable cover to the insertionunit that interfaces with the sensor unit such that removal of theremovable cover exposes the introducer and the sensor.

In some embodiments, a method of forming a sterilized sensor unit for acontinuous glucose monitor includes (1) providing a sensor, anintroducer having an insertion shaft, and an insertion shaft cover; and(2) providing a sensor housing having (a) a first end configured toreceive the insertion shaft of the introducer; (b) a second end having asealing surface configured to seal against the insertion shaft cover;and (c) an insertion shaft opening that extends between the first endand the second end and having a width that allows the insertion shaft ofthe introducer to travel through the opening, a portion of the sensorand insertion shaft of the introducer positioned within the insertionshaft opening of the sensor unit. The method further includes (3)sealingly coupling the insertion shaft cover to the second end of thesensor housing, the insertion shaft cover having an inner region; (4)inserting the introducer into the first end so that the sensor housing,the introducer and the insertion shaft cover form a sealed region thatincludes the inner region of the insertion shaft cover; and (5)sterilizing the sealed region and all components within the sealedregion.

Other features, aspects, and advantages of embodiments in accordancewith the present disclosure will become more fully apparent from thefollowing detailed description, the subjoined claims, and theaccompanying drawings by illustrating a number of example embodimentsand implementations. Various embodiments in accordance with the presentdisclosure may also be capable of other and different applications, andits several details may be modified in various respects, all withoutdeparting from the spirit and scope of the claims. Accordingly, thedrawings and descriptions are to be regarded as illustrative in nature,and not as restrictive. The drawings are not necessarily drawn to scale.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A and 1B are a side-perspective view and an exploded,side-perspective view, respectively, of a sensor assembly provided inaccordance with one or more embodiments.

FIGS. 2A and 2B are a side cross-sectional view and an exploded,side-perspective view, respectively, of a sensor unit provided inaccordance with one or more embodiments.

FIG. 3A is an exploded cross-sectional view and FIG. 3B is across-sectional view, respectively, of a sensor assembly in accordancewith an example embodiment of the disclosure.

FIG. 4A is an exploded, perspective view of an insertion device for asensor assembly provided in accordance with one or more embodiments.

FIG. 4B is a cross-sectional view of an insertion device in which aninterface unit of a removable cover is engaged with an insertion shaftcover in accordance with some embodiments.

FIG. 4C is a cross-sectional view of an insertion device in which aninsertion shaft cover is removed from a sensor assembly with a removablecover in accordance with some embodiments.

FIG. 4D illustrates a cross-sectional view of an insertion device with asliding mechanism depressed within an insertion unit during insertion inaccordance with some embodiments.

FIG. 4E illustrates a cross-sectional view of an alternative embodimentof an insertion device of FIGS. 4A-4D which employs a peelable cover inaccordance with embodiments provided herein.

FIG. 5 is a flowchart of an example method of forming a sensor assemblyfor a continuous glucose monitoring system in accordance withembodiments provided herein.

FIG. 6 is a flowchart of an example method of forming an insertiondevice for a continuous glucose monitoring system in accordance withembodiments provided herein.

FIG. 7 is a flowchart of an example method of forming a sensor unit fora continuous glucose monitoring system in accordance with embodimentsprovided herein.

DETAILED DESCRIPTION

Embodiments of the present invention allow formation of a sensor unithaving a sensor and an insertion shaft of an introducer that may beseparately sterilized and then easily and securely connected to anelectronic circuit of a continuous glucose monitor during assembly. Thesensor unit may be sterilized using a process such as electron or gammabeam sterilization which may be effective for sterilizing sensors andinsertion shafts without damaging the enzymes used by the sensors forglucose detection, but which may damage sensitive electrical circuitryof the continuous glucose monitor.

In some embodiments, the sensor unit may include a sealed, sterilizedregion formed by a sensor housing, an introducer and a cover of theinsertion shaft of the introducer. The sensor unit may form part of asensor assembly that includes a sensor carrier which joins the sensorunit to electronics for a continuous glucose monitor, while maintainingsterilization of the sensor and insertion shaft of the introducer. Insome embodiments, the sensor assembly may be employed within aninsertion device which removes the cover of the insertion shaft toexpose the sensor and insertion shaft when a cover of the insertiondevice is removed (e.g., prior to insertion).

In order to perform continuous glucose monitoring, a sensor is insertedinto a patient and electrical circuitry is coupled to the sensor. Theelectrical circuitry may be used for processing information obtainedfrom the sensor, and transmitting information to one or more externaldevices used by patients and/or healthcare providers to, among otherthings, track the patient's blood glucose level over time. A housingcontaining the electrical circuitry is adhered to the patient's skinwith the sensor extending into the patient, and remains on the patient'sskin for several days (e.g., up to a week or more in some cases).

Embodiments provided herein may simplify manufacturing of continuousglucose monitoring devices by providing a sensor unit that may beseparately sterilized and then easily and securely connected to anelectronic circuit of a continuous glucose monitor during assembly.Embodiments provided herein may also simplify the insertion process forpatients. For example, use of an insertion device which exposes thesensor and insertion shaft prior to insertion when a cover of theinsertion device is removed may reduce the number of steps a patientmust perform during insertion.

These and other embodiments of the present disclosure are describedbelow with reference to FIGS. 1A-7 .

FIGS. 1A and 1B are a side-perspective view and an exploded,side-perspective view, respectively, of a sensor assembly 100 providedin accordance with one or more embodiments. With reference to FIGS. 1Aand 1B, sensor assembly 100 includes a sensor unit 102 which fits withina sensor unit receiving area 104 of a sensor carrier 106. As will bedescribed below, sensor unit 102 includes a sensor and insertion shaftin a sterilized region of the sensor unit 102, and couples to electroniccircuitry within sensor carrier 106 when positioned within sensor unitreceiving area 104 of sensor carrier 106.

FIGS. 2A and 2B are a side cross-sectional view and an exploded,side-perspective view, respectively, of sensor unit 102 provided inaccordance with one or more embodiments. With reference to FIGS. 2A and2B, sensor unit 102 includes an insertion shaft cover 202, a top member204, a sensor 206, a spacer pad 208, a bottom member 210, a conductivemember 212, and an introducer 214 having an insertion shaft 216 andhandle 218.

Insertion shaft cover 202 covers sensor 206 and insertion shaft 216, andin some embodiments, is sealed against top member 204. For example,insertion shaft cover 202 may be sealed relative to top member 204 usingan O-ring, a sealant such as silicone, or the like. Top member 204includes an insertion shaft opening 220, defined by cylindrical member221, that extends between a first end 222 (e.g., a top surface of topmember 204) and a second end 224, and has a width that allows insertionshaft 216 to travel through the insertion shaft opening 220.

As shown in FIG. 2A, a portion of sensor 206 and insertion shaft 216 arepositioned within insertion shaft opening 220. In some embodiments,handle 218 of introducer 214 may seal against the second end 224 ofinsertion shaft opening 220 (e.g., using an O-ring, a sealant such assilicone, or the like). In this manner, insertion shaft cover 202,insertion shaft opening 220 and introducer 214 may form a sealed region226 that houses a portion of sensor 206 and a portion of insertion shaft216 that may extend within a patient during insertion. As describedfurther below, sealed region 226 and all components within sealed region226, such as sensor 206 and insertion shaft 216, may be sterilized(e.g., using an electron beam, a gamma beam, or the like)

Spacer pad 208 is configured to hold sensor 206 in position withinsensor unit 102. For example, spacer pad 208 extends the height andwidth of the internal space defined by top member 204 and bottom member210, and surrounds sensor 206 as sensor 206 extends into the internalspace defined by top member 204 and bottom member 210. In someembodiments, spacer pad 208 may be a polymer, rubber or other elastomermember and/or may be slightly compressed when positioned within sensorunit 102 between top member 204 and bottom member 210.

Space pad 208 includes a first opening 228 through which cylindricalmember 221 of top member 204 may extend, and a second opening 230through which conductive member 212 may extend. Conductive member 212may be a conductive elastomer pad, for example, that makes electricalcontact to a contact portion 232 of sensor 206 and allows sensor 206 tomake electrical contact with a substrate that supports electroniccircuitry of a continuous glucose monitor as described further below.

Bottom member 210 attaches to top member 204. For example top member 204may be glued or otherwise attached to bottom member 210, defining aninner space for sensor 206, spacer pad 208 and conductive member 212 asshown. Bottom member 210 includes a first opening 234 through whichcylindrical member 221 of top member 204 may extend, and a secondopening 236 through which conductive member 212 may extend.

In some embodiments, insertion shaft cover 202, top member 204, bottommember 210, and/or handle 218 of introducer 214 may be made fromacrylonitrile butadiene styrene (ABS), polycarbonate, nylon, acetal,polyphthalamide (PPA), polysulfone, polyethersulfone,polyetheretherketone (peek), polypropylene, high-density polyethylene(HDPE), low-density polyethelene (LDPE) or a similar material. Othermaterials may be used.

In some embodiments, sensor 206 may be made from one or more sheets,including a substrate layer such as a vinyl polymer with subsequentlayers of gold, silver chloride, and/or various coatings and enzymessuitable for the sensor's use in determining blood glucose levels. Othersensor materials may be used.

In some embodiments, insertion shaft 216 may be a hollow cylinder with asharply pointed end used to introduce a sensor into a patient'sinterstitial fluid. Insertion shaft 216 may be used to insert sensor 206into a patient such that sensor 206, or at least a portion of sensor206, is located under the patient's skin.

In some embodiments, insertion shaft 216 of introducer 214 may be madefrom a metal such as stainless steel or from another material such asplastic. In some embodiments, insertion shaft 216 is insert-molded witha plastic handle 218, and insertion shaft 216 may be, but is not limitedto, a round C-channel tube, a round U-channel tube, a stamped sheetmetal part folded into a square U-profile, a molded/cast metal part witha square U-channel profile, or a solid metal cylinder with an etched orground square U-channel. In some example embodiments, for insertionshaft 216 implemented as a C-channel or U-channel tube insertion shaft,the tube may have an inner diameter in the range of 400 μm to 700 μm anda thickness in the range of 100 μm to 250 μm. In some exampleembodiments, for insertion shaft 216 implemented as stamped sheet metalfolded into a square U-profile, the inner width and height may be in arange from 400 μm to 700 μm, with a wall thickness in a range from 100μm to 250 μm. In some example embodiments, for insertion shaft 216implemented as a molded or cast metal part, the outer diameter ofinsertion shaft 216 may be in the range of 1200 μm to 2000 μm, and innerchannel of insertion shaft 216 may have a width and height between 400μm to 700 μm. In some example embodiments, the length of introducer 214including handle 218 and insertion shaft 216 may be approximately 18 to22 mm, and the length of insertion shaft 216 of introducer 214 may beabout be approximately 12 mm to 15 mm. Other introducer and/or insertionshaft configurations, sizes and/or materials may be used.

As mentioned, sensor unit 102 includes sealed region 226 in which aportion of sensor 206 and insertion shaft 216 are housed. Followingassembly of sensor unit 102, sealed region 226, and sensor 206 andinsertion shaft 216 residing therein, may be sterilized. Examplesterilization methods include electron beam sterilization, gamma beamsterilization or any other suitable sterilization method.

FIG. 3A is an exploded cross-sectional view and FIG. 3B is across-sectional view, respectively, of a sensor assembly 100 inaccordance with an example embodiment of the disclosure. With referenceto FIGS. 3A-3B, sensor assembly 100 includes sensor carrier 106 havingsensor unit receiving area 104 and an electronics receiving area 300formed therein. Sensor carrier 106 includes a top carrier member 302coupled to a bottom carrier member 304 which couple to define theelectronics receiving area 300. In some embodiments, top carrier member302 and/or bottom carrier member 304 may be formed from the samematerial used to form top member 204 and bottom member 210 of sensorunit 102, although other materials may be used. Bottom carrier member304 includes an opening 308 through which cylindrical member 221 ofsensor unit 102 may pass when sensor unit 102 is positioned withinsensor unit receiving area 104 of sensor carrier 106.

Sensor assembly 100 includes a substrate 310 positioned withinelectronics receiving area 300. In one or more embodiments, substrate310 may be, for example, a 4-layer printed circuit board, a laminatedcircuit board, a flex circuit, a flex printed circuit board, or anyother suitable substrate for positioning and/or interconnectingelectronic circuitry (e.g., one or more insulating or dielectricmaterials with electrical conductors for connecting circuitry).Substrate 310 may be electrically non-conductive, and may haveelectrically conductive traces formed thereon and therein, for example.In some example embodiments, substrate 310 may have a thickness in arange of, but not limited to, about 0.6 mm to 0.8 mm. Other substrateand/or printed circuit board configurations, sizes and/or materials maybe employed.

Substrate 310 may have electrical circuitry 312 disposed on, and/or in,substrate 310. Electrical circuitry 312 may include circuits housed inpackages that are mounted directly to substrate 310, and/or coupled tocorresponding sockets, which are attached to substrate 310. Exampleelectrical circuitry 312 may include one or more processors, memory, abattery, a transmitter and/or receiver for communicating information toand/or receiving information from an external device, or the like. Insome embodiments, electrical circuitry 312 may be used for processinginformation obtained from sensor 206, and transmitting information toone or more external devices used by patients and/or healthcareproviders to, among other things, track the patient's blood glucoselevel over time.

As shown in FIG. 3B, when sensor unit 102 is positioned within sensorunit receiving area 104, conductive member 212 contacts substrate 310.For example, conductive member 212 may make electrical contact to one ormore electrical contacts (not shown) present on substrate 310 that are(electrically) coupled to, or which may be configured to couple to(e.g., via a switch or other similar mechanism (not shown)), electroniccircuitry 312. Conductive member 212 thereby allows sensor 206 to be inelectrical contact with electronics (e.g., electrical circuitry 312). Insome embodiments, conductive member 212 may define multiple, separateelectrical paths between sensor 206 and substrate 310 (and thuselectronic circuitry 312). For example, only predefined portions ofconductive member 212 may be electrically conductive (e.g., one or morevertical contacts that extend between sensor 206 and substrate 310).

Sensor unit 102 may be secured within sensor unit receiving area 104using any suitable mechanism (e.g., friction, adhesives, etc.).

As described, sensor unit 102 may include a sealed, separatelysterilized region 226 including at least a portion of sensor 206 andintroducer 214. Sensor unit 102 may be positioned within sensor unitreceiving area 104 of the sensor carrier 106 and electronics 312 may bepositioned within electronics receiving area 300 of sensor carrier 106so as to form sensor assembly 100 having sensor 206 electricallyconnected to electronics 312 while maintaining sterilization of thesterilized region 226 of sensor unit 102.

FIG. 4A is an exploded, perspective view of an insertion device 400 forsensor assembly 100 provided in accordance with one or more embodiments.With reference to FIG. 4A, in some embodiments, insertion device 400includes an insertion unit 402 having sensor assembly 100 positionedtherein. For example, the interior of insertion device 400 may serve asa receiving area for the sensor assembly 100. Sensor assembly 100includes sensor carrier 106 having sensor unit 102 coupled thereto.Insertion shaft cover 202 is also shown.

Insertion device 400 includes a removable cover 404 that has aninterface unit 406 that interfaces with insertion shaft cover 202 suchthat removal of removable cover 404 removes insertion shaft cover 202from sensor assembly 100 so as to expose insertion shaft 216 ofintroducer 214 and sensor 206 (FIG. 2B). For example, removable cover404 may have internal threads 408 (e.g., forming a threaded cap) thatengage with external threads 410 on interface unit 406. Interface unit406, in some embodiments, may include one or more fingers 412 a-c thatengage with corresponding notch features on insertion shaft cover 202(only one notch 414 is shown in FIG. 4A) so that rotation of removablecover 404 causes rotation of insertion shaft cover 202. Otherconfigurations for removing insertion shaft cover 202 are describedfurther below. Other numbers and/or types of fingers and/or engagementmechanisms between removable cover 404 and insertion shaft cover 202 maybe used.

In operation, when removable cover 404 is threaded onto insertion unit402, fingers 412 a-c slide within guide channels on insertion shaftcover 202 (only two guide channels 416 a-b are shown in FIG. 4A) untilthey engage in a respective notch 414. This causes the fingers 412 a-cto lock within each notch 414. FIG. 4B is a cross-sectional view ofinsertion device 400 in which interface unit 406 of removable cover 404is engaged with insertion shaft cover 202 in accordance with someembodiments. Thereafter, when removable cover 404 is unthreaded frominsertion unit 402, insertion shaft cover 202 will rotate with removablecover 404 and will be removed from sensor assembly 100 when removablecover 404 is removed from insertion unit 402. FIG. 4C is across-sectional view of insertion device 400 in which insertion shaftcover 202 is removed from sensor assembly 100 with removable cover 404in accordance with some embodiments. As shown in FIG. 4C, removal ofremovable cover 404 exposes sensor 206 and insertion shaft 216.Insertion unit 402 may then be used to insert insertion shaft 216 andsensor 206 into a patient's skin. For example, sensor assembly 100 maybe supported by a supporting member 418 within insertion unit 402. Asliding member 420 may surround sensor assembly 100 (as shown in FIG.4C) and slide relative to supporting member 418. With removable cover404 removed, sliding member 420 may be placed on the patient andinsertion unit 402 pressed toward the patient to cause insertion shaft216 and sensor 206 to be inserted into the patient's skin. A biasingmechanism, such as a spring (not shown), may bias sliding member 420 sothat it is maintained in a position around sensor assembly 100 (as shownin FIG. 4C) until insertion unit 402 is pressed for insertion. FIG. 4Dillustrates a cross-sectional view of insertion device 400 with slidingmember 420 depressed within insertion unit 402 during insertion inaccordance with some embodiments. Other insertion device configurationsmay be used.

FIG. 4E illustrates a cross-sectional view of an alternative embodimentof insertion device 400 of FIGS. 4A-4D which employs a peelable cover inaccordance with embodiments provided herein. With reference to FIG. 4E,insertion device 400 includes insertion unit 402 having a peelable cover422 formed thereon.

Peelable cover 422 may be coupled to insertion shaft cover 202 via astrap member 424, which in turn couples to insertion shaft cover 202. Inthis manner, when peelable cover 422 is removed, strap member 424 pullsand detaches insertion shaft cover 202 from sensor assembly 100,exposing insertion shaft 216 and sensor 206 for insertion (as previouslydescribed).

Peelable cover 422 and/or strap member 424 may be formed from plastic,polyethylene, high density polyethylene, Tyvek® available from E.I. duPont de Nemours and Company of Wilmington, Delaware or a similarmaterial, for example. Other peelable cover and/or strap membermaterials may be used.

In some embodiments, such as that shown in FIG. 4E, insertion shaftcover 202 may be formed from a soft and/or flexible material (e.g., aplastic bag, polyethylene, high density polyethylene, Tyvek® availablefrom E.I. du Pont de Nemours and Company of Wilmington, Delaware, or thelike). A soft and/or flexible insertion shaft cover 202 may be used withthe other embodiments described herein.

FIG. 5 is a flowchart of an example method 500 of forming a sensorassembly for a continuous glucose monitoring system in accordance withembodiments provided herein. Method 500 includes providing a sensorcarrier having a sensor unit receiving area and an electronics receivingarea, the electronics receiving area including a substrate (Block 502);providing a sensor unit having a sterilized region, the sterilizedregion including at least a portion of a sensor and an introducer (Block504); providing electronics for the continuous glucose monitoring system(Block 506); and positioning the sensor unit within the sensor unitreceiving area of the sensor carrier and positioning the electronics onthe substrate within the electronics receiving area of the sensorcarrier so as to form a sensor assembly having the sensor electricallyconnected to the substrate of the electronics receiving area whilemaintaining sterilization of the sterilized region of the sensor unit(Block 508).

FIG. 6 is a flowchart of an example method 600 of forming an insertiondevice for a continuous glucose monitoring system in accordance withembodiments provided herein. Method 600 includes providing a sensorcarrier having a sensor unit receiving area and an electronics receivingarea, the electronics receiving area including a substrate (Block 602);providing a sensor unit having a sterilized region, the sterilizedregion including at least a portion of a sensor and an introducer (Block604); providing electronics for the continuous glucose monitoring system(Block 606); positioning the sensor unit within the sensor unitreceiving area of the sensor carrier and positioning the electronics onthe substrate within the electronics receiving area of the sensorcarrier so as to form a sensor assembly having the sensor electricallyconnected to the substrate of the electronics receiving area whilemaintaining sterilization of the sterilized region of the sensor unit(Block 608); providing an insertion unit (Block 610); positioning thesensor carrier within the insertion unit (Block 612); and attaching aremovable cover to the insertion unit that interfaces with the sensorunit such that removal of the removable cover exposes the introducer andthe sensor (Block 614).

FIG. 7 is a flowchart of an example method 700 of forming a sensor unitfor a continuous glucose monitoring system in accordance withembodiments provided herein. Method 700 includes providing a sensorhousing having a first end, a second and an insertion shaft opening(Block 702). For example, the sensor unit may have a first endconfigured to receive an insertion shaft of an introducer, a second endhaving a sealing surface configured to seal against an insertion shaftcover, and an insertion shaft opening that extends between the first endand the second end and having a width that allows an insertion shaft ofthe introducer to travel through the opening. A portion of the sensorand insertion shaft of the introducer may be positioned within theinsertion shaft opening of the sensor unit. Method 700 also includessealingly coupling an insertion shaft cover to the second end of thesensor housing (Block 704); inserting an introducer into the first endof the sensor housing so that the sensor housing, the introducer and theinsertion shaft cover form a sealed region that includes the innerregion of the insertion shaft cover (Block 706); and sterilizing thesealed region and all components within the sealed region (Block 708).For example, electron or gamma beam sterilization of the sealed regionmay be performed.

While described primarily with regard to continuous glucose monitoring,it will be understood that the separately sterilizable regions describedherein, such as within the sensor units and/or sensor assemblies ofFIGS. 1A-7 , may be employed in other monitoring applications to monitorother body fluid levels such as cholesterol, HblAC, ketones, PH, oxygensaturation, etc.

An enumerated list of items (which may or may not be numbered) does notimply that any or all of the items are mutually exclusive, unlessexpressly specified otherwise. Likewise, an enumerated list of items(which may or may not be numbered) does not imply that any or all of theitems are comprehensive of any category, unless expressly specifiedotherwise. For example, the enumerated list “a computer, a laptop, asmartphone,” does not imply that any or all of the three items of thatlist are mutually exclusive and does not imply that any or all of thethree items of that list are comprehensive of any category.

A description of an embodiment with several components or features doesnot imply that all or even any of such components and/or features arerequired. On the contrary, a variety of optional components aredescribed to illustrate the wide variety of possible embodiments inaccordance with this disclosure. Unless otherwise specified explicitly,no component and/or feature is essential or required.

When an ordinal number (such as “first,” “second,” “third,” and so on)is used as an adjective before a term, that ordinal number is used(unless expressly specified otherwise) merely to indicate a particularfeature, such as to distinguish that particular feature from anotherfeature that is described by the same term or by a similar term. Forexample, a “first widget” may be so named merely to distinguish it from,e.g., a “second widget.” Thus, the mere usage of the ordinal numbers“first” and “second” before the term “widget” does not indicate anyother relationship between the two widgets, and likewise does notindicate any other characteristics of either or both widgets. Forexample, the mere usage of the ordinal numbers “first” and “second”before the term “widget” (1) does not indicate that either widget comesbefore or after any other in order or location; (2) does not indicatethat either widget occurs or acts before or after any other in time; and(3) does not indicate that either widget ranks above or below any other,as in importance or quality. In addition, the mere usage of ordinalnumbers does not define a numerical limit to the features identifiedwith the ordinal numbers. For example, the mere usage of the ordinalnumbers “first” and “second” before the term “widget” does not indicatethat there must be no more than two widgets.

The foregoing description discloses only example embodiments.Modifications of the above-disclosed apparatus and methods which fallwithin the scope of this disclosure will be readily apparent to those ofordinary skill in the art.

1. A sensor assembly for a continuous glucose monitoring system,comprising: a sensor unit, comprising: a sensor housing comprising afirst opening and a second opening; a conductive member extendingthrough the first opening; a sensor extending through the secondopening; and a sterilized region within the sensor housing, wherein thesensor is within the sterilized region and the conductive member isoutside of the sterilized region; and a sensor carrier, comprising: asensor unit receiving area for receiving the sensor unit; and anelectronics receiving area for electrically connecting to the conductivemember of the sensor unit.
 2. The sensor assembly of claim 1, whereinthe sensor unit further comprises: an introducer comprising a handle andan insertion shaft, wherein the insertion shaft extends through thesecond opening and is within the sterilized region.
 3. The sensorassembly of claim 2, wherein the handle is sealed against a bottom ofthe sensor housing, and wherein the sensor unit further comprises aninsertion shaft cover sealed against a top of the sensor housing,wherein the handle and the insertion shaft cover form a sealed regionwithin the sensor housing, the sealed region comprising the sterilizedregion.
 4. The sensor assembly of claim 1, wherein the sensor housingfurther comprises: a top member, a bottom member, and a spacer paddisposed between the top member and the bottom member, wherein thesecond opening extends from the bottom member through the spacer pad andto the top member, and wherein the first opening extends from the bottommember to the spacer pad.
 5. The sensor assembly of claim 4, wherein thesensor unit further comprises a cylindrical member extending through thesecond opening between the top member and the bottom member, and whereinthe sensor is received with in the cylindrical member.
 6. The sensorassembly of claim 5, wherein the sensor carrier comprises a thirdopening through which the cylindrical member passes when the sensor unitis positioned within the sensor unit receiving area.
 7. The sensorassembly of claim 1, wherein the sensor carrier further comprises a topcarrier member coupled to a bottom carrier member to define theelectronics receiving area.
 8. The sensor assembly of claim 1, whereinthe first opening is opposite the second opening in the sensor housing.9. An insertion device for a sensor assembly in a continuous glucosemonitoring system, comprising: an insertion unit for receiving thesensor assembly therein, wherein the sensor assembly comprises: a sensorunit, comprising: a sensor housing comprising a first opening and asecond opening; a conductive member extending through the first opening;a sensor extending through the second opening; an insertion shaftextending through the second opening; and a sterilized region comprisingthe sensor and the insertion shaft, wherein the conductive member ispositioned outside of the sterilized region; and a sensor carriercoupled to the sensor unit, the sensor carrier comprising a substrate inelectrical contact with the conductive member; and a removable coverconfigured to engage with the insertion unit, wherein removal of theremovable cover from the insertion unit exposes the sensor and theinsertion shaft.
 10. The insertion device of claim 9, wherein the sensorunit further comprises an insertion shaft cover that covers the sensorand the insertion shaft and is sealed against the second opening. 11.The insertion device of claim 10, wherein the removable cover comprisesan interface unit configured to remove the insertion shaft cover so asto expose the sensor and the insertion shaft when the removable cover isremoved from the insertion unit.
 12. The insertion device of claim 11,wherein the interface unit comprises one or more fingers that engagewith guide channels on the insertion shaft cover.
 13. The insertiondevice of claim 10, wherein the removable cover is a peelable cover, andwherein the peelable cover is coupled to the insertion shaft cover via astrap member, wherein, when the peelable cover is removed, the strapmember detaches the insertion shaft cover to expose the sensor and theinsertion shaft.
 14. The insertion device of claim 9, wherein theinsertion unit comprises external threads, and wherein the removablecover comprises internal threads that engage with the external threads.15. A continuous glucose monitoring system, comprising: an insertiondevice comprising an insertion unit having a peelable cover formedthereon; and a sensor assembly received within the insertion unit, thesensor assembly comprising: a sensor unit, comprising: a sensor housingcomprising a first opening and a second opening; a conductive memberextending through the first opening; a sensor extending through thesecond opening; an insertion shaft extending through the second opening;an insertion shaft cover covering the sensor and the insertion shaft,wherein the insertion shaft cover is coupled to the peelable cover via astrap, and wherein removal of the peelable cover removes the insertionshaft to expose the sensor and the insertion shaft; and a sterilizedregion comprising the sensor and the insertion shaft; and a sensorcarrier coupled to the sensor unit, the sensor carrier comprising asubstrate in electrical contact with the conductive member.
 16. Thecontinuous glucose monitoring system of claim 15, wherein the conductivemember makes electrical contact with the conductive member outside ofthe sterilized region.
 17. The continuous glucose monitoring system ofclaim 15, wherein the sensor unit further comprises: an introducerhaving a handle sealed against a bottom of the sensor housing at thesecond opening, and an insertion shaft cover sealed against a top of thesensor housing at the second opening to seal the sterilized region. 18.The continuous glucose monitoring system of claim 17, wherein the sensorand the insertion shaft are sterilized within the sterilized region. 19.The continuous glucose monitoring system of claim 15, wherein thesubstrate is electrically non-conductive and has electrically conductivetraces formed thereon for electrically connecting to the conductivemember.
 20. The continuous glucose monitoring system of claim 19,wherein the sensor carrier further comprises electronic circuitryelectrically coupled to the substrate, and wherein the electroniccircuitry comprises one or more processors for determining a bloodglucose level based on information received from the sensor.